This invention relates to an elevator control apparatus, and more particularly to the detection of any abnormality in the brake gear of an elevator system.
FIG. 9 shows an example of a known brake gear disclosed in the official gazette of Japanese Patent Application Publication No. 60-42151. Referring to the figure, the brake gear comprises brake arms 1, a frame 2, spring guide rods 3 which are secured to the frame 2 and on which the respective brake arms 1 are loosely fitted, compression springs 4 which are respectively fitted round the spring guide rods 3 and which afford forces urging the upper ends of the corresponding brake arms 1 in the directions of coming near to each other, bolts 5 which are threadably mounted on the respective brake arms 1, and actuating arms 6 in the shape of letter Z, both of which are pivotally mounted on the frame 2 by pins 7 and one end of each of which has its position regulated by the fore end of the corresponding bolt 5. A plunger rod 8 stands upright in abutment against the other ends of the actuating arms 6, a plunger 9 is connected to the plunger rod 8, and a housing 10 is formed of a cylindrical magnetic material provided in its bottom with a hole for loosely fitting the plunger rod 8 and is supported by the frame 2. A brake coil 11 is arranged outside the housing 10, and a braking operation-detecting switch 12 is mounted on the frame 2 and is actuated by the plunger 9.
In operation, when the brake coil 11 is energized, the plunger 9 moves down, and the plunger rod 8 depresses the actuating arms 6. Thus, the actuating arms 6 turn about the corresponding pins 7 so as to open the brake arms 1 through the corresponding bolts 5 against the forces of the compression springs 4. As a result, an electric motor not shown is released from the restraint of the brake arms 1.
Meanwhile, the movement of the plunger 9 is monitored by the operation detecting switch 12. When the operation of the plunger 9 has become abnormal due to any cause, the operation detecting switch 12 detects this situation and finds the abnormality of the brake gear.
The brake gear in the prior-art elevator control apparatus has been constructed and operated as stated above. Therefore, the mounted position of the detecting switch 12 needs to be adjusted for precisely detecting the movement of the plunger 9.
Moreover, wiring needs to be laid from the detecting switch 12 to a control panel. This is problematic in points of saving labor and conserving resources.